Controlling the transmission gear of motor vehicles



June 19, 1928. 1,674,557

K. MAYBACH CONTROLLING THE TRANSMISSION GEAR OF MOTOR VEHICLES Filed Feb. 4, 1925 4 Sheets-Sheet 1 June 19, 1928. 1,674,557 K. MAYBACH l CONTROLLING THE TRANSMISSION GEAR OF MOTOR VEHICLES Filed Feb. 4, 1925 4 Sheets-Sheet 2 26' E 1\ 27 \4 /a 7 W W A \Y\ \X\ i /4 l 3 I 73 I I 5 l 24 I, 2 J0 1/- 12 i o 5 .v

* I "Z'IJQ' J 1r" jren/orz K. MAYBACH CONTROLLING THE TRANSMISSION GEAR UP MOTOR VEHICLES 4 Sheets-Sheet 5 11 Feb. 4, 1925 V llnlllll.

A in Patented June 19, 1928.

UNITED STATES.

PATENT. OFFICE.

KARL MAYBACH, or FRIEDRICHSHAFEN, BoDnNsEE, GERMANY, AssIeuoR TO THE FIRM MAYBACH MOTOBENBAU. GESELLSCHAFT Mn: BESCHRKNKTER HAFTUNG, or FRIEDRICHSHAFEN, BODENSEE, GERMANY.

CONTROLLING THE TRANSMISSTON GEAR 013" MOTOR VEHICLES.

Application filed February 4, 1925, Serial No. 6,893, and in Germany February 8, 1924.

My invention relates to improvements in controlling the transmission gear of motor vehicles and more especially to a change speed gear.

According to' my invention 1 provide a hydraulic auxiliary device besides the usual lever operating the speed gear. This auxiliary device again controlled bythe operating lever is arranged so as to operate in one direction only. If for example a gear with two kinds of speed be provided the foot leverwill serve for actuating the means for the first speed while the auxiliarydevice actuates the second speed. Such arrangement will be of special advantage with a planet wheel gear where there is .a change clutch system. Here it would be rather difficult and troublesome for the driver to.

force in the clutch for the second speed all the time for example while riding upsteep roads. Therefore I provide the auxiliary device which will do this work after being set to operate by the foot lever. This auxiliary device may for instance be a hydraulic one and the liquid used may be oilunder the pressure of a motor driven oil pump.

Furthermore the arrangement may be made so that normally the clutch for the first speed is held. coupled by means cit-a spring against the pressure of which the foot lever may uncouple the clutch whereas the clutch for the second speed is coupled 'by the auxiliary device and is uncoupled automatically on release of this device.

The auxiliary device is cont-rolled by the foot lever in such manner that the device effects the second clutch in its coupling direction only. I preferto combine the operation of foot lever and auxiliary device by special controlling mechanism so that on the first movement of the lever over its workingangle the direct or first speed is uncoupled and that the respective clutch parts are locked in this position, whereas a second movement of the lever causes the' auxiliary device to couple the second speedwhich will be uncoupled as soon as the lever is re-.

leased. Further means may be provided which upon such release automatically couplethe first speed.

Havlng given a general description ofmy invention I now want to. point it out in (lo-- tail referring to the drawings which represent examples embodying my invention;

Fig. 1 is a side elevation of the entire arrangement wherein the hydraulic auxiliary device and the upper portion of the with a different construction of the inner clutch system.

'FIgS. 4, 5 and 6 are side elevations corresponding to Fig. 1 and showingthe different positions of the'device in operation.

The inner clutch member 1* in it's middle portion encloses an epicyclic gear comprising sun wheel 10 fixed on engine shaft 7, sun wheel 11 belonging to shaft 9, and sun wheel 12 on sleeve 13 connected to. drum 14 whichmay engage with brake cheeks 15.

Memberl may engage with outerclutch member 2 which may be the fiy wheel 'connected to disc 5. b'y screws 6- thus rotating together with engine shaft 7 the end 8 of which loosely extends into the adjoining end of driven shaft 9.

. Member 1 may engage "also against the pressure-of spring 30 tending tov press member 1 in the left hand direction.

Lever 27 is connected to a rod combined of two portions 32 and 33 which arein resilient connection with each other by means of spring 34. The free end of rod portion 33 is connected to hell crank lever 35 controlling the shaftof valve 36 of the hydraulic auxiliary device.

with outer clutch member 3 which is 1n rigid connec- This comprises oil pump 46 causing the oil to run in the directions shown by the arrows and to press on piston 39 working in cylinder 38 as soon as valve 36 closes pressure chamber 37. Piston rod 40 is linked to rod 41 which is again linked to lever 28,. so that pressure on piston 39 will resultin movement of lever 28. Piston rod 40 near to its right hand 'end has a notch 42 into which bolt 43 is pressed (by means of spring 44 resting on collar 45) as soon as the notch is moved opposite to the bolt, thereby locking rods 40 and 41 and al-. so lever 28 against backwardmovement in the left hand direction. Notch 42 and bolt. 43 are so situated relative to each other that .the locking position corresponds to the neuback to stop 25. The engine is still idle.

Now the starting switch will be actuated and the engine starts. Again the foot lever is pressed down but only for a small angle to the position shown in full lines in Fig. 6.

By this movement valve 36 is closed and while the engine begins to revolve the rising pressure of the circulating oil causes clutch member 1 to be shifted into the position shown in Fig. 6. In this step shaft 9 is driven at reduced speed. Upon release of' lever '25 the oil pressure will vanish and spring 30' will move clutch member 1 from engagement with member 3 to engagement with member 2. This movement has tobe so sudden that notch 42 will pass over bolt 43 Without allowing it to be locked. To secure such functioning I have made a spe cial construction which is shown in my -ll. S. Patenti1,549,100. Thus the position shown in Fig. 4 is attained, which means that the vehicle is moving with first speed in direct drive.

In order to attain this automatic startingot the vehicle in a perfect manner there may be used elastic means interposed-in the pressurechamber of the oil pump or in the shifting mechanism of the coupling memi her 1.

My invention is capable of various modifications to adapt the invention to varying conditions of application without deviating from the spirit of the invention.

So for instance my improvements maybe employed in connection with a transmission ear constructed in accordance with my U.

' Patent.1,505,159, of Aug. 19, 1924. Such construction is shown in Fig. 3 of my present specification. At diametrically opposite points of the planet wheel carrier 24 there are linked to clutch member 1 annular seg-' ments 1' and s after the manner ofbrake blocks. One-system of such annular segis apportioned to the cylindrical inner surface of the fly wheel rim 2, the other system of ring segments 8 to the cylindrical inner surface of the rim 3 inserted in the casing 4. The ring segments ofeach sys- 7o tem are connected with one another by toggle joint levers t, and between adjoining toggle joint levers of the two systems there is disposed the toggle arm rocking lever 42 carried by the planet wheel carrier and hav- 7-5 ing each arm linked to a toggle joint. The coupling by 'means'of the annu'lar segments a and s is efiectedby aid of powerful springs 2 which can be made to act on one or the other system by the lever 28. The lever 28 so engages with the sliding sleeve w shiftable on the planet wheel carrier 24. Connected with the sleeve to are the rods 3 and linked to a third arm of lever 1 Lever n can thus be turned by means of the lever 28 in such a manner .as to actuate the toggle lever of one system, while releasing the toggle lever of the other system. In rocking the lever 42 the pressure spring 2 the plates of which are connected with one another by a teleflu scoping rod, is rocked about-tlre pivot'disposed intermediate the two coupling rims and the ring systems. The free end of the telescoping rod carries the roller 7' which runs in contact with the double arm lever or until stopped by the bent down ends of the lever o.

What I claim is:

1. A change speed gear comprising a clutch system; said clutclr syst em compris- 10c ing two clutches; a'control lever adapted to uncouple one of said clutches; a hydraulic device controlled by said control lever and adapted to couple the other oneiof said two clutches; a spring adapted tmcouple said first clutch and to uncouple said seco'nd' clutch; and a locln'ng' device adapted to lock said clutch system in the position of both said clutches being uncoupled.

2. 'A change speed gear comprising a 1m clutch system; said clutch system comprising two clutches; means for alternately c'ou pling said-clutches; said means comprising a spring adapted to couple the first one-of said clutches and to uncouple the second one of said clutches;' a hydraulic device adapted to couple said second clutch; a foot lever adapted to uncouple the firstone of said clutches and to operate said hydraulic device; and means for locking said clutch system in its in-operative position against the pressure of said spring. a

3. A change speed gear comprising a clutch system; said clutch system comprising two clutches, means for alternately coupling said clutches, said means comprising a spring adapted to couple the first one of said clutches and to uncouple the second one oi sai'd clutches; a foot lever; and a hydraulic device; said foot lever being no by hydraulicpressure irom said pressure, chamber;

' phng said aspring adapted to couple the first. one of adapted to uncouple adapted. to uncouple the first one -.of said direction against the pressure exerted by said spring. I

.5, A change speed gear comprising a change clutch system and adapted to be the first one of said clutches and to operate said hydraulic de'- vice, said device comprising a pressure chamber, a valve controlling said press'urechamber and a piston adapted to bemoved with a hydraulic auxiliary device; the angle said piston being' adapted by means of intermediate connecting means to couple said second clutch.

fl. A change speed gear comprising a clutch system; said clutch system comprising two clutches; means for] alternately couclutches; said means comprising holding said clutch system in' direct drive;

means for uncoupling said direct driving connection on movement of said foot lever over its working "angle; means for automatically withdravvin neutralvposition on re saidclutches and 'to uncouple the second sure; a spring pressin one of said clutches; a foot lever; and a system; means for lo'c hydraulic device; said foot lever being tem in in-operative position against the pres sure of said spring adapted to cause coupling ofsa'id direct drive;

hydraulic, auxiliary ,ond speed of said change clutch system upon clutches and to operate said hydraulic device; said device comprising a pressure chamber; a valve controlling said pressure chamber and a piston adapted to be moved by hydraulic pressure from said pressure cham er; said piston being adapted to cause coupling of said second clutch;- and locking means adapted to lock said clutch system in its in-operative position but only in the.

lever and means for again uncoupling said upon thesecon'd release of In testimony whereof I afiixmy signature.

- 'KARL' MAYBACH.

of movement of said foot lever being limited by corresponding stops; means for normally said foot lever to, ease from foot 'pres-.

' against said clutch ing said clutch sysmeans/for causing said- I device to couple the secnew pressure being exerted on said foot operated; by a \foot lever 1n combination t second speed and coupling said direct drive said [foot lever. 

